We report a meta-analytic review of studies examining the relations among harmful workplace experiences and women’s occupational well-being. Based on previous research, a classification of harmful ...workplace experiences affecting women is proposed and then used in the analysis of 88 studies with 93 independent samples, containing 73,877 working women. We compare the associations of different harmful workplace experiences and job stressors with women’s work attitudes and health. Random-effects meta-analysis and path analysis showed that more intense yet less frequent harmful experiences (e.g., sexual coercion and unwanted sexual attention) and less intense but more frequent harmful experiences (e.g., sexist organizational climate and gender harassment) had similar negative effects on women’s well-being. Harmful workplace experiences were independent from and as negative as job stressors in their impact on women’s occupational well-being. The power imbalance between the target and the perpetrator appeared as a potential factor to explain the type and impact of harmful workplace experiences affecting women’s occupational well-being. In the discussion, we identify several gaps in the literature, suggest directions for future research, and suggest organizational policy changes and interventions that could be effective at reducing the incidence of harmful workplace experiences. Additional online materials for this article are available to PWQ subscribers on PWQ's website at http://pwq.sagepub.com/supplemental.
The origin of heredity in protocells West, Timothy; Sojo, Victor; Pomiankowski, Andrew ...
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
12/2017, Letnik:
372, Številka:
1735
Journal Article
Recenzirano
Odprti dostop
Here we develop a computational model that examines one of the first major biological innovations—the origin of heredity in simple protocells. The model assumes that the earliest protocells were ...autotrophic, producing organic matter from CO2 and H2. Carbon fixation was facilitated by geologically sustained proton gradients across fatty acid membranes, via iron–sulfur nanocrystals lodged within the membranes. Thermodynamic models suggest that organics formed this way should include amino acids and fatty acids. We assume that fatty acids partition to the membrane. Some hydrophobic amino acids chelate FeS nanocrystals, producing three positive feedbacks: (i) an increase in catalytic surface area; (ii) partitioning of FeS nanocrystals to the membrane; and (iii) a proton-motive active site for carbon fixing that mimics the enzyme Ech. These positive feedbacks enable the fastest-growing protocells to dominate the early ecosystem through a simple form of heredity. We propose that as new organics are produced inside the protocells, the localized high-energy environment is more likely to form ribonucleotides, linking RNA replication to its ability to drive protocell growth from the beginning. Our novel conceptualization sets out conditions under which protocell heredity and competition could arise, and points to where crucial experimental work is required.
This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.
Over the last 70 years, prebiotic chemists have been very successful in synthesizing the molecules of life, from amino acids to nucleotides. Yet there is strikingly little resemblance between much of ...this chemistry and the metabolic pathways of cells, in terms of substrates, catalysts, and synthetic pathways. In contrast, alkaline hydrothermal vents offer conditions similar to those harnessed by modern autotrophs, but there has been limited experimental evidence that such conditions could drive prebiotic chemistry. In the Hadean, in the absence of oxygen, alkaline vents are proposed to have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with relatively acidic ocean waters rich in CO2, through a labyrinth of interconnected micropores with thin inorganic walls containing catalytic Fe(Ni)S minerals. The difference in pH across these thin barriers produced natural proton gradients with equivalent magnitude and polarity to the proton-motive force required for carbon fixation in extant bacteria and archaea. How such gradients could have powered carbon reduction or energy flux before the advent of organic protocells with genes and proteins is unknown. Work over the last decade suggests several possible hypotheses that are currently being tested in laboratory experiments, field observations, and phylogenetic reconstructions of ancestral metabolism. We analyze the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria to propose a possible ancestral mechanism of CO2 reduction in alkaline hydrothermal vents. Based on this mechanism, we show that the evolution of active ion pumping could have driven the deep divergence of bacteria and archaea.
Membrane proteins are crucial in transport, signaling, bioenergetics, catalysis, and as drug targets. Here, we show that membrane proteins have dramatically fewer detectable orthologs than ...water-soluble proteins, less than half in most species analyzed. This sparse distribution could reflect rapid divergence or gene loss. We find that both mechanisms operate. First, membrane proteins evolve faster than water-soluble proteins, particularly in their exterior-facing portions. Second, we demonstrate that predicted ancestral membrane proteins are preferentially lost compared with water-soluble proteins in closely related species of archaea and bacteria. These patterns are consistent across the whole tree of life, and in each of the three domains of archaea, bacteria, and eukaryotes. Our findings point to a fundamental evolutionary principle: membrane proteins evolve faster due to stronger adaptive selection in changing environments, whereas cytosolic proteins are under more stringent purifying selection in the homeostatic interior of the cell. This effect should be strongest in prokaryotes, weaker in unicellular eukaryotes (with intracellular membranes), and weakest in multicellular eukaryotes (with extracellular homeostasis). We demonstrate that this is indeed the case. Similarly, we show that extracellular water-soluble proteins exhibit an even stronger pattern of low homology than membrane proteins. These striking differences in conservation of membrane proteins versus water-soluble proteins have important implications for evolution and medicine.
Why does workplace gender diversity matter? Here, we provide a review of the literature on both justice‐based and organizational benefits of workplace gender diversity that, importantly, is informed ...by evidence regarding sex differences and their relationship with vocational behavior and outcomes. This review indicates that the sexes are neither distinctly different, nor so similar as to be fungible. Justice‐based gains of workplace gender diversity include that it may cause less sex discrimination and may combat androcentrism in products and services. We then consider potential instrumental benefits of workplace gender diversity to organizations, including for team and firm performance, innovation, occupational well‐being, and corporate governance. The evidence of positive association is currently strongest for occupational well‐being and governance. We recommend that policy makers ground gender diversity initiatives in this comprehensive and evidence‐based understanding of the benefits of workplace gender diversity.
Reporting requirements, targets, and quotas have been implemented in several countries to increase female representation in leadership. In three studies, we analyze the effectiveness of these ...strategies from a goal-setting perspective. Study 1 evaluates the relationship between reporting requirements and female representation on boards of directors with data from Fortune 500 companies from 1996 to 2015. Study 2 analyzes the association of reporting requirements, targets, and quotas with the representation of women on boards of directors of public companies across 91 countries. Study 3 evaluates the impact of targets and quotas for women in parliaments across 190 nations. The board diversity reporting directive introduced in the US was followed by an acceleration in the increase of female representation on boards of directors of Fortune 500 companies. Higher goals for women on boards of directors were related to higher female representation. Similarly, higher gender goals and strong enforcement mechanisms in parliaments were related to higher female representation.
The ratio of non-synonymous to synonymous substitutions (dN/dS) is a useful measure of the strength and mode of natural selection acting on protein-coding genes. It is widely used to study patterns ...of selection on protein genes on a genomic scale-from the small genomes of viruses, bacteria, and parasitic eukaryotes to the largest eukaryotic genomes. In this chapter we describe all the steps necessary to calculate the dN/dS of all the genes using at least two genomes. We include a brief discussion on assigning orthologs, and of codon-aware alignment of orthologs. We then describe how to use the CODEML program of the PAML package for phylogenetic analysis to calculate the dN/dS and how to perform some statistical tests for positive selection. We then outline some methods for interpreting output and describe how one may use this data to make discoveries about the biology of your species. Finally, as a worked example we show all the steps we used to calculate dN/dS for 3,261 orthologs from six Plasmodium species, including tests for adaptive evolution (see worked_example.pdf).
Adolescent boys and young men are at particular risk of suicide. Suicidal ideation is an important risk factor for suicide, but is poorly understood among adolescent males. Some masculine behaviors ...have been associated with deleterious effects on health, yet there has been little quantitative examination of associations between masculinity and suicide or suicidal ideation, particularly among boys/young men. This study aimed to examine associations between conformity to masculine norms and suicidal ideation in a sample of adolescents.
A prospective cohort design, this study drew on a sample of 829 Australian boys/young men from the Australian Longitudinal Study on Male Health. Boys were 15-18 years at baseline, and 17-20 years at follow-up. Masculine norms (Wave 1), were measured using the Conformity to Masculine Norms Inventory (CMNI-22). Suicidal ideation (Wave 2) was a single-item from the Youth Risk Behavior Survey. Logistic regression analysis was conducted, adjusting for available confounders including parental education, Indigenous Australian identity and area disadvantage.
In adjusted models, greater conformity to violent norms (OR = 1.23, 95% Confidence Interval CI: 1.03-1.47) and self-reliance norms (OR = 1.40, 95% CI: 1.15-1.70) was associated with higher odds of reporting suicidal ideation. Greater conformity to norms regarding heterosexuality was associated with reduced odds of reporting suicidal ideation (OR = 0.80, 95% CI: 0.68-0.91).
These results suggest that conforming to some masculine norms may be deleterious to the mental health of young males, placing them at greater risk of suicidal ideation. The results highlight the importance of presenting young males with alternative and multiple ways of being a male. Facilitating a relaxation of norms regarding self-reliance, and encouraging help-seeking, is vital. Furthermore, dismantling norms that rigidly enforce masculine norms, particularly in relation to heteronormativity, is likely to benefit the broad population of males, not only those who do not conform to heterosexual and other masculine norms.
The Dark Triad traits of Machiavellianism, narcissism, and psychopathy have been found to negatively impact work behaviors including information sharing, reporting of unethical conduct, and ...mistreatment of colleagues and subordinates. However, research has found the Dark Triad can also be related to forms of organizational commitment which underpin positive work behaviors, including engaging in tasks and duties beyond those required (i.e., “going above and beyond”). Professional commitment is a broader form of commitment that has been found to be significantly related to organizational commitment, sharing antecedents, and having similar outcomes. Professional commitment, the affective, normative, and continuance commitment toward one's profession or occupation, has the benefit of applying to individuals employed by organizations as well as those working for themselves or between jobs. In this research, we explore relationships between professional commitment, using previous research on the relationship between the dark triad traits of Machiavellianism, psychopathy, and narcissism and organizational commitment, as a basis for predictions. We also explored two forms of precarious employment (career interruptions and part-time or casual work) as possible moderators of the dark triad-professional commitment relationship. Participants were 184 Australian professionals (52.2% men), a slight majority of whom had experienced a career interruption (69.6%) or a year or more of part-time or casual employment (70.7%). The results showed that psychopathy had a negative association with affective commitment, whereas Machiavellianism was positively related to normative commitment, and narcissism was positively related to normative and continuance commitment. Using regression analysis, we found that among individuals who have worked in part-time/casual employment longer, Machiavellianism and psychopathy had significantly stronger negative associations with affective commitment. In contrast, among individuals who have had a significant career interruption, Machiavellianism had significantly stronger positive association with continuance commitment. These findings help expand our understanding of both the dark triad and its contingent impact on workers' attachment to their profession.
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